Calcium Channel Blocker and Beta Blocker Poisoning
Description General measures Medicine treatment Referral T44.7/T46.1 + (X43.99/X63.99/Y14.99) DESCRIPTION Cardiovascular toxicity results in profound hypotension, bradycardia, decreased systemic vascular resistance and cardiogenic shock. Depressed level of consciousness and metabolic acidosis are due to poor tissue perfusion. Hyperglycaemia and hypokalaemia may occur. Patients who have co-i
T44.7/T46.1 + (X43.99/X63.99/Y14.99)
DESCRIPTION
Cardiovascular toxicity results in profound hypotension, bradycardia, decreased systemic vascular resistance and cardiogenic shock. Depressed level of consciousness and metabolic acidosis are due to poor tissue perfusion. Hyperglycaemia and hypokalaemia may occur. Patients who have co-ingested other cardiac medicines and those with pre-existing cardiac disease are at increased risk of morbidity.
The treatment of suspected cardiogenic shock in calcium channel blocker and beta blocker poisoning follows similar therapeutic principles. The mainstay of treatment is high-dose insulin euglycaemic therapy (HIET) and inotrope and vasopressor infusions.
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GENERAL MEASURES
- Monitor vital signs, ECG and blood glucose.
- Treat symptomatic patients in consultation with a specialist.
MEDICINE TREATMENT
- Caution is advised for all decontamination procedures as they increase vagal tone and may exacerbate bradycardia.
- Activated charcoal may be considered before the onset of symptoms.
- Whole bowel irrigation can be considered for ingestion of modified-release preparations.
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Bradycardia: R00.1 + (T46.1/X44.99/X64.99/Y14.99)
- Atropine, IV 0.5–1 mg every 2–3 minutes to a maximum of 3 mg.
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Hypotension: I95.9 + (T46.1/X44.99/X64.99/Y14.99)
- Start with sodium chloride 0.9%, IV.
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If not effectively controlled
ADD
- Calcium gluconate 10%, IV, 30 to 60 mL given over 15–30 minutes, with ECG monitoring.
- This may be repeated a maximum of 4 times.
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- Simultaneously use vasopressors and inotropes as needed, e.g. adrenaline (epinephrine) infusion for persistent hypotension (see: Cardiac arrest in adults) or dobutamine for bradycardia (see: Cardiogenic shock) and refer patient immediately.
REFERRAL
All patients requiring HIET should be treated in a High Care or ICU setting
Standard Treatment Guidelines and Essential Medicines List for South Africa, Adult Hospital Level, 2020-2024_Version 2.0_27 March 2025
Chapter 19 Poisoning_19.11 Calcium Channel Blocker and Beta Blocker Poisoning
Drugs mentioned
ICD-10 codes
- I95.9Hypotension, unspecified
- R00.1Bradycardia, unspecified
- T44.7Poisoning, beta-adrenoreceptor antagonists, not elsewhere classified
- T46.1Poisoning, calcium-channel blockers
- X43.99Accidental poisoning by and exposure to other drugs acting on the autonomic nervous system, unspecified place, during unspecified activity
- X44.99Accidental poisoning by and exposure to other and unspecified drugs, medicaments and biological substances, unspecified place, during unspecified activity
- X63.99Intentional self-poisoning by and exposure to other drugs acting on the autonomic nervous system, unspecified place, during unspecified activity
- X64.99Intentional self-poisoning by and exposure to other and unspecified drugs, medicaments and biological substances, unspecified place, during unspecified activity
- Y14.99Poisoning by and exposure to other and unspecified drugs, medicaments and biological substances, undetermined intent, unspecified place, during unspecified activity